Strange logic in SiteSection

The ctor to the class SiteSection takes amongst its parameters a list of jsp pages to include and an integer "visiblePages" such that only the first those pages up to index visiblePages-1 have links in the GUI. This is silly and hard to maintain (See NAS-2298 for an example of it going wrong). Just create a new ctor that takes two lists - one of visible pages, one of invisible pages - concatenates them, and passes the list to to the existing (now private) ctor.